Intra-oral denture correlator



Nov. 10 1942. c. s. BALLARD INTRA'ORAL DENTURE CORRELATOR 2 Sheets-Sheet 1 Filed Sept. 20. 1939 INVENTOR. CA r/as .5. //am c. s. BALL ARD INTRA- ORAL DENTURE; v CORRELATOR Nov. 10, 1942.

-2 Sheets-Sheet 2 Filed Sept 2o.. 193s as gothic arch tracing.

manner of the devices application for, and here Patented Nov. 10, 1942 umren s'rres er NT orrics 6 Claims.

This invention relates to dental equipment and especially to an intra-oral device for advancing the practice of dentistry in the production and fitting of artificial dentures, and for its general object aims to provide equipment of this nature functioning in its application to denture plates to obtain a smooth and harmonious relation in all working conditions of a patients lower in relation to the upper jaw, whether the artificial teeth be produced in the form of full dentures in opposition, a full denture against a partial, or a full denture against natural teeth. The technique practiced is essentially one of correlating in which the instant device serves the end of stabilizing the dentures which are inserted within the mouth relative to the patients jaw processes, and it is by this.termcorrelator-that I will hereinafter refer to the instrument of my invention insofar as the same is used to perform the said stabilizing ofiice.

With the foregoing and further more particular objects and advantages in view, the nature of which will appear in the course of the following description and claims, the invention consists in the novel construction and in the adaptation and combination of parts hereinafter described and claimed.

. It may be here stated that my instrument in its preferred embodiment has been produced in a manner which, in addition to its operation as a correlator, permits what is known in dentistry While I illustrate the inafter describe the use in, gothic arch tracing, no claim is made therefor in that the salient feature of an expansive agent operative to yieldingly influence, by intra-oral application, a full denture directively from an opposing full denture, or from an opposing partial denture, or from opposing natural teeth, and which is responsible for the accomplishment of my correlating end, is entirely inoperative in the employment of the instrument for gothic arch tracing.

In the drawings:

Figure 1 is a view in side elevation representing the invention as the same is applied in the performance of gothic arch tracing.

Fig. 2 is a vertical section on the longitudinal median line thereof.

Fig. 3 is a transverse vertical posterior cross section on line 33 of Fig. 1.

Fig. 4 is a transverse vertical posterior cross section indicating the application of the invention, for correlating purposes, to upper and lower artificial dentures. i p

Fig. 5 is a vertical section on the longitudinal median line of Fig. 4 and modified therefrom in that the dentures are shown in separated relation to one another for the insertion therebetween of carbon paper from which, through the markings transferred to irregular or high cusps, milling may be carried on to effect true correlation.

Figs. 6, 7 and 8 are perspective views detailing parts of the present invention shown in the preceding views, namely the mounting base and the bearing and scratch plates thereof.

Fig. 9 is a vertical section to an enlarged scale detailing the several parts of the invention as the same are assembled for correlating purposes, the mounting base and the bearing plate being shown fragmentarily; and

Fig. 10 is an elevational View of the correlator pin.

' The invention, in its preferred form, provides a mounting base H of an approximate'horseshoe plan configuration scarped to produce a marginal flange l2 along both sides and about the curved end and with the underside arched, this base piece being somewhat smaller in its perimetrical com- 'pass than the inner-edge limits of a lower bite plate or denture, as the case may be, to which the same is adapted to be applied. Such application, in the case of the bite plate represented in Figs. 1 through 3 and denoted by the letter a, is accomplished by heating the base piece and pressing the warm flange into the wax of which the bite plate is composed, the application to a lower artificial denture, denoted by in Figs. 4 and 5, being accomplished by the use of a plastic compound p. The position occupied by the base piece in both of such applications is such that the facing surface lies flush with or slightly above the occlusal surface, the arched underside providing ample tongue room to relieve any strained feeling of such organ.

Complementary to the mounting base and adapted to be fixed by plastic compound p to the upper bite plate or the upper artificial denture, as the case may be, in proximate but spaced parallel relation to the base piece is a plane bearing plate l3 generally conforming in its marginal compass-to that of the base. This bearing plate, as applied to a bite plate, is or may be surfaced with a replaceable thin scratch plate M on which gothic arch tracing is recorded, the scratch plate which is terminally hooked as at 4 being fixed in position by wax w.

Reverting to the mounting base, in the approxiimate center thereof, considered both transversely and longitudinally, the same is tapped to form a threaded socket [5 for the reception of a vertically adjustable and reversible hollow screw l6 serving as a bearing for a correlator pin I! which, at one end I1, is pointed and, at the other end I1, is characterized by a rounded head. Immediately adjacent said ends are annular grooves and lodged therein are rings [8 and [9. Ring l8 by abutment with the end wall of the screw limits the axial travel of the pin under the influence of a compression spring seating within a counterbore I6 of the screw and bearing against a collar 2| abutting the other ring 19.

In performing gothic arch tracing, the technique of which is well known, the lower bite plate a and its complementing upper plate b have their bite rims built only in the anterior region, terminating at each side in the lateral incisor regions. The invention is applied in the manner shown in Figs. 1 through 3, which is to say with the pointed end of the correlator pin uppermost, following which the screw is turned to bring the point ll into engagement with the scratch plate I4. So employed, the spring 20 is inoperative other than to bring the ring l8 into firm seating engagement with the screw. The patient is instructed to hold centric and the dentist introduces to the upper and lower bite plates what may be referred to as centric aligners, consisting of two square pieces of thin sheet metal, these aligners which I indicate by dotted lines in Fig. 2 and denote by in being warmed and pressed into the wax of the bite plates to line up anteriorly and laterally. Upon completing the tracing steps which are recorded on the scratch plate I4 through movement of the patients jaws through anterior and lateral travel, these tracings being visible to the dentist through a retraction of the patients cheek with a mouth mirror, the two bite plates with the centric aligners even are fixed in relation to one another by application of plaster c which is inserted from opposite sides of the mouth by a spatula. The bite plates, then removed with my intra-oral device intact, are readily mounted on an articulator by which the determined bite characteristics of the patient are incorporated in artificial dentures.

In correlating these artificial dentures the invention is applied in the manner indicated in Figs. 4 and 5, which is to say with the rounded end ll" of the correlator pin uppermost, the screw being adjusted to obtain the desired tension of the spring whose office is to yieldingly spread the upper denture g from the lower denture ,f and thereby hold the same firmly against the underlying tissues of the patients jaws.

It will, it is thought, be clearly understood that in the performance of correlating work the dentures are caused to rise and fall as the cusps of one denture pass over the cusps of the other denture and ride along the inclined surfaces into the so-called valleys, or sulci, between the teeth, and my spring agent serves the obvious ofiice of maintaining a firm seating engagement of the dentures against the underlying tissues of the patients upper and lower jaws throughout the correlating procedure, which is to say while the one denture rises and falls in relation to the other denture by oscillatory movement given to the seated dentures by shifting of the patients jaws. Otherwise stated, the device-as a correlator--is an instrument which stabilizes the dentures permitting the latter to move in unison with the patients jaws, the spring agent pressing outwardly in opposition to the closing movement of the jaws to maintain a continuing firm seating contact of the dentures upon the underlying tissues irrespective of the rise and fall as contact is had between cusp-and-cusp, and cusp-andsulci.

It will be readily realized that a shifting movement of the patients jaws permits the dentist, through the instrumentality of placing carbon paper between the teeth, to accurately ascertain the high spots by the resulting transfer of markings from the paper to the teeth, and that, by milling oif these high spots, the dentist is permitted to accurately relate the teeth of the dentures to the patients true chewing processes.

It is to be understood, and it is believed to be apparent, that numerous modifications are within the spirit of the invention and it is therefore my intention that the hereto annexed claims be given a scope in their interpretation commensurate with the state of the advance in the art of dentistry, which said advance, as a generic state ment, can be said to consist broadly of an intraoral spreader arranged to be applied between full dentures in opposition, a full denture against a partial, or a full denture against natural teeth and having two functional characteristics-first, an ability to freely contract and expand in correspondence with the rise and fall of the denture plates and, second, an ability to accommodate itself to unrestrained oscillatory movement as between the denture-carrying jaws. I consider it self-evident that the use of the terms upper dentures and lower dentures in the several claims are to be liberally construed as meaning any applicable member or members on which my correlating procedure may be performed.

What I claim is:

1. In an intra-oral dental device: the combination of a base piece adapted to be fixed to the lingual surface of a lower denture; a bearing plate providing a substantially plane facing surface and adapted to be fixed in the palate of an upper denture to have said facing surface occupy, within the mouth of the patient, a plane proximate to but spaced above the plane occupied by the base piece and approximately parallel with the crest of said upper dentures ridge; a bearing member having a thread mounting in the base piece permitting the same to be adjusted toward and from the bearing plate; a pin slidably journaled in said threadably mounted bearing member for movement approximately at right angles to the crest of the lower dentures ridge or, otherwise stated, at approximate right angles to the patients occlusal plane; and a spring finding a footing against the threadably mounted bearing member and acting on the pin to urge the latter upwardly from the bearing member into contact with said facing surface of the bearing plate to yieldingly influence the two dentures, one from the other, and thereby seat the dentures firmly in the mouth, said adjustment of the bearing member toward and from the bearing plate operating in the respective instance to increase and decrease the spring pressure and thereby increase and decrease the compression of the tissues of the patients mouth which lie under the dentures, said pin being formed to have its contacting tip track freely over said facing surface of the bearing plate for permitting uninterrupted oscillatory motion of the lower in relation to the upper of the patients two dentures.

2. In an intra-oral dental device: the combination of a base piece adapted to be fixed to the lingual surface of a lower denture; a bearing plate providing a substantially plane facing surface and adapted to be fixed in the palate of an upper denture to have said facing surface occupy, within the mouth of the patient, a plane proximate to but spaced above the plane occupied by the base piece and approximately parallel with the crest of said upper dentures ridge; a pin carried by the base piece for sliding movement approximately at right angles to the crest of the lower dentures ridge or, otherwise stated, at approximate right angles to the patients occlusal plane; and a spring acting on said pin to urge the latter upwardly into contact with said facing surface of the bearing plate to yieldingly influence the two dentures, one from the other, and thereby seat the dentures firmly in the mouth, said pin being formed to have its contacting tip track freely over said facing surface of the bearing plate for permitting uninterrupted oscillatory motion of the lower in relation to the upper of the patients two dentures.

3. In an intra-oral dental device: the combination of a base piece adapted to be fixed to the lingual surface of a lower denture; a bearing plate providing a substantially plane facing surface and adapted to be fixed in the palate of an upper denture to have said facing surface occupy, within the mouth of the patient, a plane proximate to but spaced above the plane occupied by the base piece and approximately parallel with the crest of said upper dentures ridge; and a spring-actuated expander carried by said base piece and urged by the spring upwardly from the base piece into contact with said facing surface of the bearing plate for yieldingly influencing the two dentures, one from the other, and thereby seating the dentures firmly in the mouth, said expander being characterized in that its contacting tip, which is to say the part thereof which contacts the facing surface of the bearing plate, is formed to allow a free tracking movement over said facing surface to permit uninterrupted oscillatory motion of the lower in relation to the upper of the patients two dentures.

4. In an intra-oral dental device: the combination of a pair of complementary elements of which one is adapted to be fixed to the lingual surface of a lower denture and the other fixed in the palate of an upper denture and with one of said elements providing a substantially plane facing surface which, in the application of the dental device within the mouth of the patient, is arranged to occupy a plane proximate to but spaced from the plane occupied by the other element and approximately parallel with the crest of its related dentures ridge; and an expanding member carried by the other of said fixed elements and spring-actuated directively from its supporting element into contacting engagement with the plane facing surface of said complementing element, thereby to yieldingly influence the two dentures, one from the other, and seat the dentures firmly in the mouth, said expanding member being formed to have its contacting tip, which is to say the part thereof which engages said plane facing surface, track freely over said facing surface for permitting uninterrupted oscillatory motion as between the patients two dentures.

5. A dental device according to claim 4 having adjustment means for increasing and decreasing the effective expansion pressure of the spring which acts on the expanding member, thereby to increase and decrease the compression of the tissues of the patients mouth which lie under the dentures.

6. In an intra-oral dental device, in combination: a member adapted to be fixed to one of a set of upper and lower dentures to lie within the dental arch thereof; an expander-element carried by said fixed member and spring-urged outwardly from the supporting denture in a direction approximately at right angles to the plane occupied by the ridge of the latter; and a member complementary to said first-named member adapted to be fixed to the other denture to lie within the dental arch of the latter and providing an element arranged, in the application of the dental device within the mouth of the patient, to find footing engagement with and receive the expansive thrust of said expander-element for yieldingly influencing the two dentures, one from the other, and thereby seating said dentures firmly in the mouth, said expander and footing elements being unattached and being characterized in that one of such elements provides a relatively fiat bearing face disposed to lie approximately parallel with the crest of its related dentures ridge and the other of such elements a working extremity arranged to bear upon and track freely over such bearing face to permit uninterrupted oscillatory movement of the one as respects the other of the two dentures.

CHARLES S. BALLARD. 

